We've been renovating our lawn for about three years now. Our first serious and most effective step was to power rake the lawn, spread well-aged compost to 1/2", and overseed with high quality grass seed. It made such a difference, people stopped and commented on the improvement. We continued to apply soil amendments like compost and over-seeding tough areas until last fall.
We mow high in the spring and summer to help shade out weed seedlings, increase drought tolerance and make the grass look lusher. Lower setting for fall as grass goes dormant. We always leave clippings to decompose naturally.
We switched this year to corn gluten. I didn't use it before because we had large areas that needed re-seeded. Corn gluten works against weeds by allowing them to sprout but not spread roots. New grass is also affected. So it made the most sense for us to work on improving the soil and growing grass where needed, then switch to maintenance weed control and feeding. Corn gluten breaks down and provides nitrogen to the grass as well, so it is a natural weed and feed.
It does cost more than 4 bags of Scotts, I will admit. And our yard is not weed free in the conventional sense. We have some dandelions, clover, and other weeds. But it is not mostly weeds, the grass is so healthy looking, it looks greener and lusher than the 'lawn service' lawn next store. I don't worry about my kids playing on it, we have tons of earthworms in the soil, the wildlife is happy, I'm happy.
We have a lawn that is barefoot worthy!
I bought my corn gluten at Garden's Alive, they call it WOW, but I wouldn't buy it there again. Here is a link
describing why with some other resources.